need help runtime error

hi i was playing around with blender 2.4 and did some yafray hdri renders all went fine for a few it crashes after a few minutes while rendering.
i tried reinstalling yafray & blender but nothin seems to work.
ps with a few objects it works fine but when i try my complete model of 100 + objects,not even all with material or texure it crashes.
plz help me out
here’s a screenshot